Microtrap on a concave grating reflector for atom trapping  

作　　者：张慧 李涛 尹亚玲 李兴佳 夏勇 印建平 

机构地区：[1]State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University [2]National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University

出　　处：《Chinese Physics B》2016年第8期397-401,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11374100,91536218,and 11274114);the Natural Science Foundation of Shanghai Municipality,China(Grant No.13ZR1412800)

摘　　要：We propose a novel scheme of optical confinement for atoms by using a concave grating reflector.The two-dimension grating structure with a concave surface shape exhibits strong focusing ability under radially polarized illumination.Especially,the light intensity at the focal point is about 100 times higher than that of the incident light.Such a focusing optical field reflected from the curved grating structure can provide a deep potential to trap cold atoms.We discuss the feasibility of the structure serving as an optical dipole trap.Our results are as follows.（i） Van der Waals attraction potential to the surface of the structure has a low effect on trapped atoms,（ⅱ） The maximum trapping potential is ~1.14 mK in the optical trap,which is high enough to trap cold ^87Rb atoms from a standard magneto-optical trap with a temperature of 120 μK,and the maximum photon scattering rate is lower than 1/s.（ⅲ） Such a microtrap array can also manipulate and control cold molecules,or microscopic particles.We propose a novel scheme of optical confinement for atoms by using a concave grating reflector.The two-dimension grating structure with a concave surface shape exhibits strong focusing ability under radially polarized illumination.Especially,the light intensity at the focal point is about 100 times higher than that of the incident light.Such a focusing optical field reflected from the curved grating structure can provide a deep potential to trap cold atoms.We discuss the feasibility of the structure serving as an optical dipole trap.Our results are as follows.（i） Van der Waals attraction potential to the surface of the structure has a low effect on trapped atoms,（ⅱ） The maximum trapping potential is ~1.14 mK in the optical trap,which is high enough to trap cold ^87Rb atoms from a standard magneto-optical trap with a temperature of 120 μK,and the maximum photon scattering rate is lower than 1/s.（ⅲ） Such a microtrap array can also manipulate and control cold molecules,or microscopic particles.

关 键 词：subwavelength structures high-contrast gratings beam focusing laser trapping 

分 类 号：O562[理学—原子与分子物理]